软土地基上预制预应力圆筒风机基础的侧向土压力研究

我国内陆风场开发迅猛发展,沿海风场由于所采用风机基础形式的造价和现场施工的难度较高而没能得到大规模开发.预制预应力圆筒风力发电塔基础作为一种应用于沿海潮间带或内陆湿地等软土地区的新型风机基础形式,具有造价低、施工快等优点,具有良好的实际应用和市场推广价值.由于软土地区风机基础的抗弯承载力主要由基础侧向土压力分布情况决定,而在《钢结构单管通信塔技术规程》(以下简称《规程》)中的刚性短柱基础验算地基承载力时采用的侧向土压力计算简图与有限元分析得出的侧向土压力分布结果相差较大.本文通过数学方法对圆筒基础的侧向土压力分布曲线的有限元分析结果进行拟合,得到了圆筒基础周围土压力是随深度呈1.5次方曲线变化的结论,并将其与《规程》简图和有限元分析的曲线对比,说明1.5次方曲线应用在该基础的抗弯承载力设计中是可行的.最后,将基于1.5次方曲线的设计方法应用到工程实例当中与板式独立基础进行对比,说明了新方法的经济与合理性.

Research on Side Pressure of Prefabricated Prestressed Cylinder Foundation of Wind Turbines in the Soft Soil Region

With the rapid development of inland wind farm in China,the costal wind farm still has not gotten large-scale development as the result of the higher cost of fan foundation and the more difficulty of construction.The prefabricated prestressed cylinder foundation(PPC foundation),as a new type of wind turbine foundation designed for the soft soil region such as the inter-tidal coastal zone and inland wetlands,has the advantages of low project cost and rapid construction with good value of application and market spreading.The condition of lateral earth pressure distribution around the foundation which determines the flexural capacity of fan foundation in the soft soil exists big differences between finite element method result and simplified calculation of《Technical Specification for Steel Communication Monopole》.Through theoretical analysis and mathematical derivation,the result shows that the lateral earth pressure around PPC foundation is changed with depth by 1.5 th power curve which has good fitting to the finite elemeol analysis result and that is proved to be feasible in bending capacity design after contrast with the other two curves.The improved design process is applied into the practical engineering to compare with the traditional foundation design ana the good economy and reasonability of new foundation is proved.